The present invention relates to a device for applying edge banding to panels, especially panels of various different shapes, made of wood, plastic or similar materials and used preferably to make items of furniture.
At present, the operation by which edge banding, usually a strip of synthetic material, is glued to the edges of panels with curved profiles is carried out using equipment of various kinds, based on the different constructional principles followed by different manufacturers of woodworking machinery.
This equipment consists basically of a work table on which the panel to be edged is placed and means for applying the edging. The work table and the means for applying the edging move relative to each other so that the edging can be glued right round the perimeter of the panel.
By way of example, one solution for a piece of equipment of this kind is disclosed in German patent application DE - OS 35.17.194 in which the work table, with the panel on it, can rotate about a vertical axis, while the edge banding application means, comprising a roller that presses on the edge band while the latter is being fed, are driven only along the longitudinal axis of the machine in such a way as to copy the profile of the panel as it comes into contact with the pressure roller.
A more recent solution is disclosed in patent publications EP 276.358 and EP 510.231 which describe an apparatus that has a fixed table, to which the panel is secured, and a carriage equipped with an arm that mounts the devices for feeding the edge band, applying the edge band, machining the edge and cutting off the edge band. The carriage moves along two controlled axes X and Y above and in parallel with the surface of the panel to apply the edge band to the panel and finish the edge.
These solutions envisage the use of pre-glued edge banding which, just before being applied to the panel, is heated in such a way as to reactivate the glue. The disadvantage of this method is that, since the amount of glue forming the layer of pre-applied glue must be limited, it is not always enough to "cover" the pores in the edge of the panel. In short, machines of this kind sometimes work with "less than sufficient glue".
There are also "through" machines, that is to say, linear edge banding machines designed to apply edge bands to panels with straight edges and in which the panel is fed relative to the edge banding device, which remains fixed: with these machines, the glue may be applied either to the panel or to the edge band.